1. Field of the Invention
The present invention relates to a humidity sensitive device.
More specifically, the present invention relates to a novel humidity sensitive device mainly including semiconductive ceramics.
2. Description of the Prior Art
Generally a humidity sensitive device utilizes a property of an electrical resistance of a substance which is changeable as a function of a humidity. The characteristics required for such humidity detecting device are high reliability, a long life, a practically measurable range such as a resistance R=10-10.sup.7 .OMEGA., stability in a gas atmosphere, a relatively small temperature dependency, utilizability at a low and high temperature such as 100.degree. C., and the like; however, present few if any humidity sensitive devices meeting such ideal conditions are available.
For example, one known humidity sensitive device utilizing organic macro molecules is unsatisfactory in reliability and life. A second known humidity sensitive device having a pair of electrodes formed on a magnetite film of 30.mu. in thickness also has too short a life. A third humidity sensitive device of a nickel ferrite group has also been developed and announced but has not been put into practical use, because it is difficult to manufacture and mass production of good reproductibility is doubtful.